1. Field of the Invention
The present invention is broadly concerned with an improved wood substitute product having many physical properties similar to that of wood (e.g., sawability, specific gravity and fastener retention) while being relatively inexpensive to fabricate and having a very long useful life. More particularly, it is concerned with such wood substitutes and methods for fabrication thereof, wherein the product includes an outermost, tubular casing with a cured fill including respective amounts of cement and synthetic resin foam; the presence of substantial amounts of synthetic resin foam in the cementitious fill has been found to give the wood substitute product many of the desirable qualities of wood.
2. Description of the Prior Art
The provision of acceptable, low-cost wood substitutes has long been a goal of many researchers in the art. It is known to provide wood substitutes formed entirely of synthetic resin materials such as polystyrene or polyvinyl chloride. However, these products are high in cost owing to the amount of synthetic resin employed, and are not price competitive with natural wood. Moreover, these products can degrade due to the effect of UV light or other environmental conditions. Finally, such synthetic resin products have only a limited ability to retain fasteners (particularly nails) and thus cannot be used in many applications where a wood substitute would otherwise be a viable alternative to natural wood.
Cement/fiber composites have also been used in the past to create high strength materials for specialized construction applications. For example, carbon fiber and synthetic resin fiber reinforced cement concretes are disclosed in U.S. Pat. Nos. 4,968,561, 5,030,282 and 5,032,181. However, these products are not useful as wood substitutes.
There is therefore a need in the art for a truly useful and cost-effective wood substitute which mimics the desirable properties of wood such as sawability, specific gravity and the ability to hold a variety of fasteners including nails.